1. Field of the Invention
The present invention relates to an injection-molded product manufactured with synthetic resin materials, and more particularly, to an injection-molded product having light permeability.
2. Description of the Related Art
Generally, an injection-molded product has a predetermined shape, which is manufactured by melting synthetic resin, injecting the melt synthetic resin into a molding die, and then curing it. Most products manufactured using synthetic resin manufactured by injection molding are in daily use, including kitchen utensils, bathroom articles, home appliances, cellular phones, and vehicle interior materials,
Recently, various portable electronic devices such as cellular phones, MP3 players, portable multimedia players, portable game consoles, etc. have come into wide use, outer cases are typically made of injection-molded products. Users of portable electronics regard their portable electronic devices as fashion items like accessories. Thus, manufacturers of the portable electronic devices are putting efforts to sophisticate and diversify the design.
The electronic devices, by their nature, are costly in research, development and manufacturing stages prior to becoming actual products. Although electronic devices are typically made with metallic cases and have to overcome problems such as an electric leakage, electromagnetic interference, and so forth.
The electric leakage or electromagnetic interference is alleviated by mainly using injection-molded products as cases of portable electronic devices. For sophisticated exteriors, a surface treatment is performed using painting, deposition, printing, and plating. Alternatively, a film having a color or pattern on a surface thereof is put into a molding die in advance such that film coating is performed simultaneously with molding (film insert injection molding). However, portable electronic devices, because of being carried and frequently manipulated by a user, are likely to be exposed to an external environment, thus being prone to a scratch as a result of drop or mishandling. As a result, the case manufactured with surface treatment or film insert injection molding may easily experience damages to its color or pattern. Moreover, there is a limitation in forming a 3D color or pattern on the case surface.
In recent times, injection-molded products having light permeability have been used to manufacture the cases of the portable electronic devices. In case of the light-permeability injection-molded product, a color or pattern, even when being formed on an inner surface of the product, can be seen from outside, so that the color or decorative pattern is not deteriorated by damage, such as a fall or scratch, to an outer surface of the product. However, since the case of the electronic device can be a complete case only by coupling between an injection-molded product and a counterpart injection-molded product, a hook for coupling with the counterpart or a boss for screw engagement has to be formed. However, there is a drawback in that the injection-molded product having permeability with such coupling structures are visible from outside.
In manufacturing permeable injection-molded products, when colors or patterns are formed on an inner surface, painting or deposition should be performed with dark colors to prevent internal coupling structures from being visible from outside. In spite of surface treatment, such as painting or deposition, on the inner surface with dark colors, the coupling structures on the inner surface of the injection-molded product cannot be completely hidden.
An inner surface 10a of a permeable injection-molded product 10, which has red-type paints deposited thereon, is shown in FIG. 1, and an outer surface of the injection-molded product 10 is shown in FIG. 2. As shown in FIGS. 1 and 2, on the inner surface 10a of the injection-molded product 10 are formed coupling structures 11 and 13 and a reinforcement structure 15 for reinforcing rigidity. To hide the internal coupling structures 11 and 13, such surface treatment as painting or deposition is performed on the inner surface 10a of the injection-molded product 10, whereby the injection-molded product 10 looks reddish from outside. However, as can be seen in FIGS. 1 and 2, only with the surface treatment, the coupling structures 11 and 13 or the reinforcing structure 15 cannot be completely hidden from the outer surface of the injection-molded product 10.
Therefore, there is a need to enhance visual and design features, in manufacturing a case with a permeable injection-molded product, so that coupling structures can be entirely hidden to provide an elegant exterior casing for fashion conscious portable users.